Propeller tail-shafts of ships



United States Patent 1 3,540,405

[ 72] Inventor John A. Clay [56] References Cited gz g s UNITED STATES PATENTS [2]] Appl. No. i

2 232 225 $1322 51:: -s-ss 12 ,452 1 Patented 3'407'779 l0/l968 s :1 m 't 115/54 [73] Assignee Turnblill Marine Design Company Limited a er e [32] Priority April 25 1967 Primary Examiner-Trvgve Bllx 33] Grea l t Britain AttorneyStevens, Davis, Miller and Mosher [31] 19,057/67 ABSTRACT: A stern bearing for the tail-shaft of a ship is split to enable part of the bearing to be removed while the ship is [54] PROPELLER TAIL'SHAFTS 0F SHIPS afloat to enable inspection of the tail shaft, and hydraulic jack 8 claims 4 Drawing Figs means are provided for urging the removable bearing part into [52] US. Cl 115/34 a shaft encasement position and for removing the removable [5]] Int. Cl B63h 5/06, bearing part from the shaft. The bearing extends asfar as a B63h 23/32 propeller flange on the tail-shaft, and a water-tight seal encir- [50] Field of Search 1 15/34, 0.5 cles the bearing.

Patented Nov. 17, 1970 Sheet INVE/VTDR Jomv p,

'7 MW -L ATTURA/Ey;

Patented Nov. 17, 1970 3,540,405

Sheet 3 of4 II MEIW R ITO/M ACLH/ HTTDRIV 5V5 PROPELLER TAIL-SHAFTS F SHIPS The present invention relates to stem bearings for the propeller tail-shaft of ships.

It has previously been proposed to provide a ship whose tailshaft is so encased in and supported by a split bearing that at least part of the bearing is removable to enable inspection'of the tail-shaft without disturbance of any part operative to propel the ship and while the ship is still afloat.

The present invention provides a ship whose propeller tailshaft is so encased in and supported by a split bearing that at least part of the bearing is removable to enable inspection of the tail-shaft without disturbance of any part operative to propel the ship and while the ship is still afloat, wherein hydraulic jack means are provided for securing the bearing in a shaft encasement position around the tail-shaft, the hydraulic jack means being operable to withdraw at least part of the bearing from said position.

The present invention further provides a stern bearing ar rangement for a propeller tail-shaft, comprising a split bearing having a first bearing part and a second bearing part adapted to be pressed towards the first bearing part into a shaft encasement position, in a manner enabling removal of said other part, by operation of hydraulic jack means, wherein the hydraulic jack means are operable to withdraw the second bearing part from the shaft encasement position.

The invention will be more readily understood from the following description of an embodiment thereof given by way of example with reference to the accompanying drawings, in which:

FIG. 1 shows a broken-away view in longitudinal cross section through a stern bearing arrangement;

FIG. 2 shows a view taken in section along the line 11-11 of FIG. 1;

FIG. 3 shows in greater detail a longitudinal section, broken away, through a double-acting hydraulic jack forming part of the stern bearing arrangement of FIG. 1; and

FIG. 4 shows a diagrammatic view of a hydraulic control circuit for the stern bearing arrangement of FIG. 1.

As shown in FIG. 1 the stern frame of a ship is formed in one piece with a lower housing part 11 which cooperates with an upper housing part 12 to encase two bearing liners 14 and 15 around a tail-shaft 16. A flange 18 formed on the tail-shaft 16 is bolted to the boss 19 ofa propeller.

The housing parts 11 and 12 and the bearing liners 14 and 15 form a split bearing which projects partially from the stern frame 10, and which extends rearwardly along the tail-shaft 16 to a position adjacent the flange 18.

A mechanical seal 22 seals a ring member 23, which is bolted on the stern frame 10, to a ring member 24 bolted to the flange 18, the mechanical seal 22 extending around the portion ofthe split bearing projecting from the stern frame 10. A further mechanical seal 26 seals the forward end of the split bearing to the tail-shaft 16.

The upper housing part 11 is secured in position on the tailshaft 16 by two hydraulic. jacks indicated generally by reference numerals 28.

As shown in FIGS. 1 and 3 each hydraulic jack 28 has a double-acting piston 30 having its piston head in a cylinder 31 formed on the upper housing part 11 and provided at its other end with an end cap 32 which abuts a seat 33 formed on the stern frame 10. Each cylinder 31 is closed above by a cylinder cover 35 secured by bolts to the cylinder 31 and having an opening through which the piston 30 extends. A tapped collar 38 is in threaded engagement with the piston 30. Adjustment of the collar 38 along the piston 30 is effected by means of a tommy bar (not shown) engaged in peripheral holes 39 in the collar 38 the two collars 38 then being retained by a turnbuckle 40, shown in broken lines in FIG. 1, which is engageable in holes 41 (FIG. 3) in the collars 38.

Each piston 30 extends freely through a carriage 43 (FIGS. 2 and 3) having wheels 44 which can roll along a track formed by two rails 45 extending parallel to the tail-shaft 16.

As shown in FIG. 4, a hydraulic circuit for controlling the jacks 28 comprises a hand pump 47 with a built-in air reservoir for pumping oil through a pipe 48 to a manually operable control valve 49 which is adjustable from the position shown. in which the oil flow to and from the hydraulic jacks 28 is interrupted so that the oil returns through a pipe 50 to the hand pump 47, to allow oil flow to a pipe 51a or a pipe 51b The pipe 51a is connected through two shutoff valves 52 and two flexible hoses 53 to'couplings 54 and 55, while the pipe 51!; is connected through a further two shutoff valves 52 and a further two flexible hoses 53 to couplings 56 and 57. The couplings 54 and 57 communicate respectively with the spaces above and below the head of the piston 30 in the forward cylinder 31, while the couplings 55 and 56 are connected by pipes 59 and 60, respectively, to the spaces above and below the head of the piston 30 in the aft cylinder 31.

To secure the upper housing part 11 in the position shown in FIG. 1, the control valve 49 is operated to supply oil to the pipe 51b and thereby to extend the hydraulic jacks 28 between the cylinders 31 and the seats 33 so that the upper housing part 11 and the bearing liner 15 are urged downwards into the shaft encasement position in which they are shown in FIG. 1. The collars 38 are then tightened against the casing members 37 to lock the hydraulic jacks 28.

To remove the upper housing part 11 and therewith the upper bearing liner 15, the collars 38 are slackened, the hydraulic jacks 28 being extended to permit this, and the operation of the hydraulic jacks 28 is then reversed, by supplying oil to the pipe 51a so that they contract, whereupon the end caps 32 move downwardly free of the seats 33 until the end caps 32 rest on the carriages 43. Continued retraction of the hydraulic jacks 28 then raises the upper housing part 11 and the bearing liner 15 from the tail-shaft 16. The upper half of the split bearing, comprising the upper housing part 11 and the bearing liner 15, together with the hydraulic jacks 28, can then be moved forward by rolling the carriages 43 along the rails 45.

The tail-shaft 16 is than accessible for inspection as far as the flange 18 from within the ship, and while the ship is afloat,

without disturbing any part operable to propel the ship.

As shown in FIG. 1, the split bearing extends through an opening in the stern frame 11 providing a clearance 64 between the edge of the opening and the top of the bearing. This opening is large enough to allow a solid forged coupling on the forward end of the tail-shaft 16 to pass through the stern frame 10 when the tail-shaft 16 is inserted into or removed from the ship. A radial seal 65 on the upper bearing part 11 makes sealing contact with a radial face 66 on the stern frame 10 for sealing this clearance 64.

Since the split bearing supports the tail-shaft 16 rearwardly to a position adjacent the flange 18, the length of the split bearing may be shorter, in comparison to the diameter of the tail-shaft 16, than has hitherto been considered necessary from tail-shaft bearings. It has been found that the ratio of bearing length to shaft diameter may be from As: I to 2:1.

While the abovedescribed embodiment employs a flanged tail-shaft, the invention may also be used with a flangelcss tailshaft, the stern frame then being sealed to the propeller boss. Moreover, the invention is not restricted to the use of double acting hydraulic jacks since one or more jacks may be pro vided only for urging the upper half of the bearing downwardly into the shaft encasement position, one or more further jacks being provided for lifting the upper half of the bearing.

I claim:

1. In a ship, a stern bearing arrangement comprising means defining an opening in the stern frame, a propeller shaft extending through said opening, a split bearing extending into said opening, said split bearing comprising a bearing part which is removable to allow inspection of said shaft from within the ship, means defining a radial spacing between said removable bearing part and the inner periphery of said opening to permit the removal of said removable bearing part, seal means for preventing the entry of water into the ship through said opening, and means for releasably urging said removable bearing part into position on said shaft.

2 A ship as set forth in claim 1, wherein said split bearing has a portion protruding rearwardly of said opening.

3. A ship as set forth in claim 2, wherein said seal means comprises a mechanical seal extending around the rearwardly protruding portion of said split bearing.

4. A ship asset forth in claim 1 wherein said split bearing extends rearwardly to a position adjacent a propeller flange on said shaft.

5. A ship as set forth in claim 1, and further comprising 

